The invention relates to a large capacity blow-moulded lidded drum (wide-necked packing drum) made of thermoplastic plastic for storing and transporting hazardous liquid or solid contents, having a substantially conical drum body which has, on its outer wall in the vicinity of the upper charging opening, a circumferential surface flange for the gas- and liquid-proof fastening of a drum lid by means of an overlapping tension ring, a stacking rim being provided on the outer wall of the drum body in the region of the upper third of the drum to allow a plurality of such conical lidded drums to be stacked one inside the other.
The invention does not relate to small conical packing drums manufactured using the injection moulding technique, such as, for example, paint buckets or the like.
Conical lidded drums, when empty, may be stacked one inside the other and therefore offer the major advantage that, despite their large dimensions, they are economical in terms of freight space and cost during dispatch and are correspondingly economical to store when empty.
A conical plastic lidded drum of the type described is known, in which the drum body is provided with a discontinuous step-like diameter increase in the region of its upper third, with the drum wall being cylindrical from said diameter increase up to the upper drum opening. By virtue of the projecting wall step, an outer stacking rim is provided and an upper lidded drum nested into a lower drum may be supported on the upper drum rim of the charging opening of the lower drum, thereby preventing a plurality of nested drums from becoming wedged one inside the other so that they are virtually impossible or require a great deal of effort to separate again. Said drums, in a stable construction with an appropriate wall thickness, have proved successful as reusable packaging. In the case of lightweight drums of reduced wall thickness, however, the stability under load of a stack could become limited or critical when a plurality of full drums are stacked one on top of the other.
Another conical industrial drum is provided in its upper wall region with a plurality of spaced-apart calottes, which are formed so as to project outwards and each have on their outer bottom edge an axial stop face as a stacking edge. As a result, however, there are corresponding pockets or partial bulges in the drum inner wall which are a drawback in the final stages of emptying the drum because residues of adhesive contents may remain in said pockets and make it difficult to clean the drums for re-use.
A plastic rain barrel having an, in particular, conical drum body is also known. This rain barrel of a different generic type is, however, a stationary container and is also not suitable for transporting, in particular, hazardous liquid or solid contents because the barrel cannot be tightly sealed. Admittedly, the uppermost rim of the charging opening is flanged outwards almost at right angles and forms the supporting surface for a barrel lid which is inserted into the barrel opening and rests on the flanged rim but, in the absence of a sealing facility and a difference in diameter between barrel flange and lid rim, said barrel lid cannot be fixed by means of a tension ring in a liquid-proof manner on the barrel opening. Nor was there in any way provision for this because the lid has a non-closable central inlet opening for the collection of rain water and moreover merely serves, for example, to prevent leaves or other particles from falling into the barrel.